.Zohar Behar
This study begins a 20 paragraphs long article about the unification of the Holy One Blessed be He and the Shechinah.
The word for ‘sacrifice’ is ‘קרבן’, which has the root word ‘קרב’ that means ‘coming closer’.
Moses, the Faithful Shepherd, in this Zohar explains that the Shechinah is ‘sacrifice’ to YHVH. When the Shechinah is close to him with all her parts, which is the Sefirot, in complete unification of male and female, there is oneness and state of completion.

2 Kings 4:34
“וַיַּעַל וַיִּשְׁכַּב עַל-הַיֶּלֶד, וַיָּשֶׂם פִּיו עַל-פִּיו וְעֵינָיו עַל-עֵינָיו וְכַפָּיו עַל-כַּפָּו, וַיִּגְהַר, עָלָיו; וַיָּחָם, בְּשַׂר הַיָּלֶד”
“And he went up and lay on the child, and put his mouth on his mouth and his eyes on his eyes and his hands on his hands, and he stretched himself on him; and the flesh of the child became warm.”

This verse from the story about Elisha the prophet describes how he brought to life a boy of a woman who hosted and served him in her house. He laid on the boy connecting his sefirot of Zeir Anpin to the body, that is the aspect of Malchut, bringing the Light and the soul back into the child’s body. The prophet was on a high spiritual level and could do that connection.
The Zohar teaches us with this story that for unification of Light and vessel we need a connection on all levels.

A man without a woman is like half a person. We need to build a proper vessel / a good reason for desiring the Light. It shoud have the aspects of the sefirot Chessed, Gevurah and Tiferet. Chessed for pure and kind consciousness, Gevurah to express the desire for the Light and Tiferet is the purpose that binds Chessed and Gevurah together as one.
Our most important prayers always mention Abraham, Isaac and Jacob. They represent the three columns.

The purpose of Kabbalah is to bring the unification of Light and Vessel, Zeir Anpin and The Shechinah/Malchut. When we do that we can conclude our prayer with Zecharia 14:9 (at the end of עלינו לשבח)
“וְהָיָה יְהוָה לְמֶלֶךְ, עַל-כָּל-הָאָרֶץ; בַּיּוֹם הַהוּא, יִהְיֶה יְהוָה אֶחָד–וּשְׁמוֹ אֶחָד”
“And YHVH shall be king over all the earth: in that day shall there be YHVH one, and his name one.”

‘His name’ is the ‘expression’ of YHVH in this world and the aspect of the vessel. The oneness is the body of male and female in complete unison.